/kræb; kræb/
n
1 (a) [C] ten-legged shellfish 蟹. =>illus at shellfish 见shellfish之插图.
(b) [U] its flesh as food 蟹肉
*dressed crab, ie prepared for eating 加作料的蟹肉.
2 the Crab [sing] the fourth sign of the zodiac; Cancer 巨蟹宫（黄道第四宫）; 巨蟹星座.
3 [C] (infml 口) = crab-louse.
4 (idm 习语) catch a crab => catch1.

/kræb; kræb/
v (-bb-) [I, Ipr] ~ (about sth) (infml derog 口, 贬) complain; grumble; criticize 抱怨; 挑剔; 批评
*The boss is always crabbing about my work. 老板对我的工作总是横挑鼻子竖挑眼.

n

[Sense: 1-3; Origin:Old English crabba]
[Sense: 4; Date: 1800-1900; Origin: crabbed]
[C]
a sea animal with a hard shell, five legs on each side, and two large claws
→crustacean
[U]
the flesh of this animal that you can cook and eat
　crab meat
　dressed crab (=prepared for eating)
crabs [plural]informal
a medical condition in which a type of louse (=insect) is in the hair around sexual organs
[singular]AmE informal someone who becomes annoyed easily about unimportant things